Fix optionnal size field
Fix optionnal size field

etalab/udata,opendatateam/udata,davidbgk/udata,etalab/udata,jphnoel/udata,grouan/udata,grouan/udata,etalab/udata,jphnoel/udata,davidbgk/udata,jphnoel/udata,opendatateam/udata,opendatateam/udata,grouan/udata,davidbgk/udata